import math
x1, y1, x2, y2 = [float(i) for i in input().split()]
print(math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)) import math math float(i) for i in input().split() for i in input().split() i input().split() ().split () input split for i in input().split() float(i) float i x1, y1, x2, y2 = [float(i) for i in input().split()] x1 [float(i) for i in input().split()] y1 x2 y2 print(math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)) print math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) math.sqrt math sqrt (x1 - x2) ** 2 + (y1 - y2) ** 2 (x1 - x2) ** 2 x1 - x2 x1 x2 2 (y1 - y2) ** 2 y1 - y2 y1 y2 2 x1, y1, x2, y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] x1 y1, x2, y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] y1 y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] y2 x2, y2 = [float(i) for i in input().split()] [float(i) for i in input().split()] x2
import math
x1, y1, x2, y2 = [float(i) for i in input().split()]
print(math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2))